The present invention relates generally to improved apparatus for mass production manufacturing, and in a presently preferred form, to an apparatus for dynamically regulating input and output workloads to achieve efficient operations.
In one form, an apparatus made according to the invention receives continuous input of separate articles such as can ends in long "strings", and subdivides them into individual arrays or "sticks", in which form the ends or like articles are handled so as to insure that the output of one or more manufacturing machines may be accommodated by one or more additional processing machines located downline or downstream thereof, while permitting all such machines to operate either continuously or intermittently without loss of production.
The preferred form of apparatus includes means for transiently storing excess sticks of can ends, for example, in containers such as open top trays which are filled stick by stick with the can ends; the trays may also be previously filled and act as the source of the main supply, or an extra or supplementary supply of ends which are in turn fed to machines downstream of the apparatus. Thus, the sticks of ends may be sent directly downstream or stored transiently, and the outbound end supply may be supplemented from time to time by sticks of ends taken from storage.
Referring to the preferred form of apparatus, this unit consists of what may be referred to as a load regulator and includes a magazine for storing a series of empty trays, a magazine for storing a series of full trays, a transfer assembly for picking up sticks of can ends and sequentially loading them into predetermined areas of empty storage trays to fill the trays, or, in the alternative, to unload full trays of ends, stick by stick. All such operations are done under automated control to insure that temporary dislocations and transient changes of machine output and demand rates will not affect the overall productivity of an industrial operation.
By way of further background, for example, the can manufacturing industry is one wherein high quality products, and product components, must be routinely manufactured at incredibly high rates while maintaining exceptionally high quality. It is not now unknown for the shells from which complete can ends are made, to be manufactured in a single press at rates of up to 3,500 shells per minute from a single die press. Machines are now being built wherein the manufacturing rate from a single machine having two sets of dies will produce 5,200 shells per minute, and still further improved machines are in prospect which will produce up to 7,000 or more shells per minute. Multiple machines, of course, add to the manufacturing speed potential in this and other industries.
As is typical with many modern industrial operations, the overall manufacturing operation is subdivided into a plurality of individual component-making steps, and each of these steps is further subdivided into a sequence of further individual steps. As the cyclic rates of manufacturing machines increases, the importance of flexibility in manufacturing becomes apparent.
Quite clearly, only brief dislocations with machinery downstream of manufacturing machines operating at these speeds could either cause excess "stack-up" of parts forced to be arrayed and transiently stored before difficulties or delays in the downstream machines has been accomplished. Often, the upstream machines are simply stopped because transient storage has been impractical. By the same token, if a very high speed upstream machine is to be stopped briefly for machine repair or inspection, it is almost always still desirable to maintain continuous operation of machines downstream of such inactivated machine. This requires that articles be available from storage, since the articles are not then being manufactured. Effective workload regulation is likewise desirable under these circumstances.
Referring specifically to one application of the workload regulator of the present invention, manufacturing can ends in the beer and beverage industry is subdivided into a shell press operation wherein feedstock, usually in coil form, is supplied to a press which, with each stroke, produces a plurality of can ends from coiled sheet stock. These ends are in the form of metal disks to which a substantial third dimension or countersink has been imparted, and to which a so-called curl has also been imparted. These individual can end shells emerge from the shell presses in a plurality of strings, which strings of ends are then fed to a downstream machine such as a so-called end liner. The liner fills the peripheral channel or curl in the can end with a plastisol or like gasket-forming material which is necessary to form a fluid and gas-tight seal between the end and the can body when the two are seamed together after the can has been filled.
In one form, after end shells are stamped or drawn and curled, and after they have been aligned, the can ends thus formed are fed to so-called conversion presses wherein an easy-opening feature is imparted to the can end by scoring a tear-out area and affixing a pull tab to it. The conversion presses are customarily fed a supply of can ends and a continuous roll of aluminum tab sheet stock material. Easy-opening ends thus formed are then stored on site or transferred to the can filling site.
With can making equipment being operated at such phenomenal speeds, it is considered ideal to have the operating speeds of the machines and the numbers of such machines carefully matched so as to avoid transient over-or under-capacity during manufacturing. However, this idea is rarely able to be maintained in practice, for reasons of maintenance requirements, unforeseen breakdowns, changes in scheduling, or the like. If these events occur, as they often do, it is still desired to maintain the projected manufacturing rate in spite of discontinuity and/or dislocation.
Even when a relatively minor breakdown occurs, for example, in one area of the manufacturing operation, this in turn may necessitate undesirable alternatives of ceasing manufacturing, or being required to a accommodate temporary over-capacity by storing a partially manufactured product; this action itself creates its own set of problems, namely, that of attending to quality control in an interrupted manufacturing operation.
At present, the possibility of manufacturing dislocations with presently known high speed machines is such that can end manufacturing is customarily accommodated by non-automated feeding and transfer between machines.
According to the present invention, steps previously performed by hand are able to be accomplished in a fully or partially automated manufacturing operation, with the potential of dramatic cost savings and increased production being achieved with an actual increase in product quality.
In view of the failure of the prior art to provide effective methods and apparatus for the regulating or balancing the output of plural mass production machines with the handling capacity of machines located downstream or downline thereof, it is an object of the present invention to provide an improved workload regulator for industrial operations.
Another object of the invention is to provide a workload balancer or regulator to be used in the can making industry.
Yet another object of the present invention is to provide an apparatus for handling mass produced high quality products such as can ends, and, in particular, to receive continually manufactured quantities of such products from plural sources, and to transiently array them in groups and place the groups in temporary storage, while simultaneously transferring other of such products directly to a downstream work station, with inflow and outflow being controlled so as to balance or regulate differing rates of article production or supply, and demand or capacity.
A further object of the invention is to provide apparatus for handling mass produced parts such as can ends and which includes a plurality of stations, including an accumulation station for receiving plural, substantially continuous inputs or "strings" of can ends, an inbound staging area at which the strings are subdivided into individual arrays or "sticks", an apparatus for transferring such sticks of can ends into any one of a plurality of tracks in an outbound staging areas, or in the alternative, to a storage position, and wherein the subdivision into sticks, storage of incoming sticks and feeding and/or supplementing of outgoing sticks is accomplished as a part of a single, ongoing process.
Another object of the invention is to provide an apparatus which is capable of storing plural arrays or sticks of articles such as can ends, and continually adding to or taking from the stored quantity of such articles, as indicated by the quantity of articles being fed to the apparatus on the one hand and being accommodated by machines downline of the apparatus on the other hand.
Yet another object of the invention is to provide an apparatus for handling can ends or the like which includes means for receiving plural strings of can ends from individual shell-forming machines, means for subdividing a plurality of such strings of ends into individual sticks, means for temporarily storing such sticks while additional strings of ends are being fed to the apparatus, and means for repositioning such sticks of ends, in the alternative, into an outbound staging area, into an inventory build-up area, as well as transfer means for individual sticks from a previously established storage or built-up inventory area.
A still further object of the invention is to provide a workload regulator which includes a number of storage containers, storage areas within each of the containers for accommodating a plurality of products arrayed in individual groups, a magazine for accommodating a plurality of containers filled with articles, and a magazine for accommodating a plurality of empty containers, and which further includes means for positioning one container being filled or emptied to a succession of positions within a transfer station area, so that the containers may serve as a variable-capacity transient storage area for the purpose of balancing inbound and outbound quantities of such products.
Yet another object of the invention is to provide a workload regulating apparatus which includes plural work stations adapted to handle, respectively, trays or like containers of products, being filled with such products, trays from which said products are being emptied, means for subdividing incoming products into individual arrays, and means for removing such arrays of outgoing products with a control apparatus being provided for determining the incoming supply rate and the outgoing demand rate, and for selectively positioning incoming arrays of articles so they may be placed directly into an outbound staging area or stored transiently so as to accomplish the objective of regulating the flow rate of the artcles between work stations without slowing down the production rate of such stations.
A still further object of the invention is to provide a workload balancer which is adapted to remove arrays of individual products from storage and advance them to work stations downline of the apparatus from an inventory of such materials, even when the apparatus is not receiving freshly manufactured products so as to continue to supply products downline of the appartus during a cessation of upline manufacturing.
Yet another object of the invention is to provide an apparatus of the type just described which further includes means for moving additional articles to more permanent storage areas and removal from such more permanent storage areas, whether or not such storage areas serve as a portion of the regulating or balancing apparatus.
A yet further object of the invention is to provide a system for regulation of the supply and demand for component parts in an industrial process which includes at least one storage container with a plurality of storage areas, including means for adding groups of articles to, and taking them from, the storage areas, and means for moving the container in either direction relative to a storage and retrieval area at which such parts are added to and taken from storage, together with a control system which moves the container in both directions so as to provide a supply of groups of articles to be taken from storage when needed and to provide a container for transiently storing articles when required.
Another object of the invention is to provide a load regulator for an industrial process wherein a continuous stream of articles may be subdivided into groups for handling, and to which apparatus includes two magazines each adapted to receive a plurality of storage trays received within the magazines, and a conveyor for transporting a container from the first magazine to the second magazine, and from the second magazine back to the first, with one magazine being adapted to receive full trays, the other magazine adapted to receive empty trays, and the conveyor being adapted to move a container which is being filled or being emptied between a plurality of positions to facilitate groupwise additions to or retrievals from the carrier, in combination with a control which moves the container toward the full container magazine when article groups are being added to the container, and for moving the container toward the empty container magazine while article groups are being taken from the container.
Another object of the invention is to provide a method for balancing the work flow of a supply of articles created by machines and being fed in a continuous array toward a production line destination which includes removing inbound articles in groups from an inbound lane area and transferring them to an outbound lane area, determining when the number of articles called for by the production line destination is less than the number of articles being received from the source, periodically removing groups of articles from the inbound area and placing them in trays for transient storage, and when the number of articles called for by the destination exceeds the number being received from the production source, supplementing the supply of articles being fed from the inbound lane areas to the outbound lane areas by removing additional articles from storage and adding them to the articles being transferred directly from the inbound lane to the outbound lane.
Still another object of the invention is to provide a method as described above which further includes periodically placing trays filled with the articles in a filled tray storage area, and periodically removing the empty trays to an empty tray storage area, so as to provide at least one individual tray receiving or providing groups of articles, and full and empty trays to provide respectively additional stored articles and storage capacity.
A further object of the invention is to provide a method of balancing the rate at which articles being supplied from a first, upstream work station with the demand for such articles at a second, downstream work station, which method includes providing at least one inbound staging area for receiving the articles from the first work station, and an outbound staging area for advancing articles to the second, downstream work station, and continually removing the articles in groups from said inbound staging area and transferring them to the outbound staging area, and when the number of articles called for by the second work station is less than the number of articles being received at the inbound staging area, periodically removing groups of articles from the inbound staging area and placing them in selected areas of storage containers for transient storage, and when the number of articles called for by the second work station exceeds the number of articles being received from the first work station, removing the articles in groups from the storage areas of the containers and adding such groups of articles from time to time to the groups of articles already being transferred directly from the inbound staging area to the outbound staging area.
The foregoing and other objects and advantages of the invention are achieved in practice by providing an apparatus which includes means for receiving a continual supply of manufactured articles, transiently arraying the articles in groups and transferring them from an inbound staging area in which they are arrayed to an outbound staging area for movement downstream of the apparatus, which apparatus may also transiently place some or all of the inbound groups of articles in temporary storage, instead of transferring them to the outbound staging area, and which may remove groups of articles from the storage area to supply them to the outbound staging area as a supplement to the groups of articles being directly supplied to the outbound staging area.
The apparatus also includes mechanisms for arraying, loading, and storing both empty and full containers for groups of products, including means providing bi-directional movement of the storage containers to permit the rate at which articles are placed in or removed from storage to be changed from time to time.
The objects and advantages of the invention are also achieved by providing a method of regulating the rate at which articles being supplied from a first work station are advanced to a second work station, which includes receiving inbound articles in a staging area and advancing at least some of them to an outbound staging area, as well as transferring groups of inbound articles to transient storage areas instead of to the outbound area and, in the alternative, supplementing the supply of outbound articles by adding groups of articles taken from the storage area to the outbound groups.
The manner in which the foregoing objects and advantages are achieved in practice will more clearly be apparent when reference is made to the following detailed description of the preferred embodiments of the invention wherein like reference numbers indicate correspondence of the drawings.